﻿#include <iostream>
#include <eigen3/Eigen/Eigen>
#define WINGDIAPI
#include <osgEarth/GeoData>

using namespace std;

const double epsilon = 0.000000000000001;
const double pi = 3.14159265358979323846;
const double d2r = pi / 180;
const double r2d = 180 / pi;

const double a = 6378137.0;		//椭球长半轴
const double f_inverse = 298.257223563;			//扁率倒数
const double b = a - a / f_inverse;
//const double b = 6356752.314245;			//椭球短半轴

const double e = sqrt(a * a - b * b) / a;

void Blh2Xyz(double& x, double& y, double& z)
{
	double L = x * d2r;
	double B = y * d2r;
	double H = z;

	double N = a / sqrt(1 - e * e * sin(B) * sin(B));
	x = (N + H) * cos(B) * cos(L);
	y = (N + H) * cos(B) * sin(L);
	z = (N * (1 - e * e) + H) * sin(B);
}

void Xyz2Blh(double& x, double& y, double& z)
{
	double tmpX = x;
	double temY = y;
	double temZ = z;

	double curB = 0;
	double N = 0;
	double calB = atan2(temZ, sqrt(tmpX * tmpX + temY * temY));

	int counter = 0;
	while (abs(curB - calB) * r2d > epsilon && counter < 25)
	{
		curB = calB;
		N = a / sqrt(1 - e * e * sin(curB) * sin(curB));
		calB = atan2(temZ + N * e * e * sin(curB), sqrt(tmpX * tmpX + temY * temY));
		counter++;
	}

	x = atan2(temY, tmpX) * r2d;
	y = curB * r2d;
	z = temZ / sin(curB) - N * (1 - e * e);
}

void TestBLH2XYZ()
{
	//double x = 113.6;
//double y = 38.8;
//double z = 100;	   
//   
//printf("原大地经纬度坐标：%.10lf\t%.10lf\t%.10lf\n", x, y, z);
//Blh2Xyz(x, y, z);

//printf("地心地固直角坐标：%.10lf\t%.10lf\t%.10lf\n", x, y, z);
//Xyz2Blh(x, y, z);
//printf("转回大地经纬度坐标：%.10lf\t%.10lf\t%.10lf\n", x, y, z);

	double x = -2318400.6045575836;
	double y = 4562004.801366804;
	double z = 3794303.054150639;

	//116.9395751953      36.7399177551

	printf("地心地固直角坐标：%.10lf\t%.10lf\t%.10lf\n", x, y, z);
	Xyz2Blh(x, y, z);
	printf("转回大地经纬度坐标：%.10lf\t%.10lf\t%.10lf\n", x, y, z);
}

void CalEcef2Enu(Eigen::Vector3d& topocentricOrigin, Eigen::Matrix4d& resultMat)
{
	double rzAngle = -(topocentricOrigin.x() * d2r + pi / 2);
	Eigen::AngleAxisd rzAngleAxis(rzAngle, Eigen::Vector3d(0, 0, 1));
	Eigen::Matrix3d rZ = rzAngleAxis.matrix();

	double rxAngle = -(pi / 2 - topocentricOrigin.y() * d2r);
	Eigen::AngleAxisd rxAngleAxis(rxAngle, Eigen::Vector3d(1, 0, 0));
	Eigen::Matrix3d rX = rxAngleAxis.matrix();

	Eigen::Matrix4d rotation;
	rotation.setIdentity();
	rotation.block<3, 3>(0, 0) = (rX * rZ);
	//cout << rotation << endl;

	double tx = topocentricOrigin.x();
	double ty = topocentricOrigin.y();
	double tz = topocentricOrigin.z();
	Blh2Xyz(tx, ty, tz);
	Eigen::Matrix4d translation;
	translation.setIdentity();
	translation(0, 3) = -tx;
	translation(1, 3) = -ty;
	translation(2, 3) = -tz;

	resultMat = rotation * translation;
}

void CalEnu2Ecef(Eigen::Vector3d& topocentricOrigin, Eigen::Matrix4d& resultMat)
{
	double rzAngle = (topocentricOrigin.x() * d2r + pi / 2);
	Eigen::AngleAxisd rzAngleAxis(rzAngle, Eigen::Vector3d(0, 0, 1));
	Eigen::Matrix3d rZ = rzAngleAxis.matrix();

	double rxAngle = (pi / 2 - topocentricOrigin.y() * d2r);
	Eigen::AngleAxisd rxAngleAxis(rxAngle, Eigen::Vector3d(1, 0, 0));
	Eigen::Matrix3d rX = rxAngleAxis.matrix();

	Eigen::Matrix4d rotation;
	rotation.setIdentity();
	rotation.block<3, 3>(0, 0) = (rZ * rX);
	//cout << rotation << endl;

	double tx = topocentricOrigin.x();
	double ty = topocentricOrigin.y();
	double tz = topocentricOrigin.z();
	Blh2Xyz(tx, ty, tz);
	Eigen::Matrix4d translation;
	translation.setIdentity();
	translation(0, 3) = tx;
	translation(1, 3) = ty;
	translation(2, 3) = tz;

	resultMat = translation * rotation;
}

void TestXYZ2ENU()
{
	double L = 116.9395751953;
	double B = 36.7399177551;
	double H = 0;

	cout << fixed << endl;
	Eigen::Vector3d topocentricOrigin(L, B, H);
	Eigen::Matrix4d world2localMatrix;
	CalEcef2Enu(topocentricOrigin, world2localMatrix);
	cout << "地心转站心矩阵：" << endl;
	cout << world2localMatrix << endl << endl;

	cout << "站心转地心矩阵：" << endl;
	Eigen::Matrix4d local2WolrdMatrix;
	CalEnu2Ecef(topocentricOrigin, local2WolrdMatrix);
	cout << local2WolrdMatrix << endl;




	double x = 117;
	double y = 37;
	double z = 10.3;
	Blh2Xyz(x, y, z);

	cout << "ECEF坐标（世界坐标）：";
	Eigen::Vector4d xyz(x, y, z, 1);
	cout << xyz << endl;

	cout << "ENU坐标（局部坐标）：";
	Eigen::Vector4d enu = world2localMatrix * xyz;
	cout << enu << endl;

	
	x = 40400;
	y = 0;
	z = 600;
	Eigen::Vector4d xyz1(x, y, z, 1);
	Eigen::Vector4d ecef = local2WolrdMatrix * xyz1;
	cout << ecef << endl;

	x = ecef[0];
	y = ecef[1];
	z = ecef[2];
	Xyz2Blh(x, y, z);

	cout << "B,L,H" << x << "," << y << "," << z;
}

void TestOE()
{
	double L = 116.9395751953;
	double B = 36.7399177551;
	double H = 0;

	osgEarth::SpatialReference* spatialReference = osgEarth::SpatialReference::create("epsg:4326");//wgs84
	osgEarth::GeoPoint centerPoint(spatialReference, L, B, H);

	osg::Matrixd worldToLocal;
	centerPoint.createWorldToLocal(worldToLocal);

	cout << fixed << endl;
	cout << "地心转站心矩阵：" << endl;
	for (int i = 0; i < 4; i++)
	{
		for (int j = 0; j < 4; j++)
		{
			printf("%lf\t", worldToLocal.ptr()[j * 4 + i]);
		}
		cout << endl;
	}
	cout << endl;

	osg::Matrixd localToWorld;
	centerPoint.createLocalToWorld(localToWorld);

	cout << "站心转地心矩阵：" << endl;
	for (int i = 0; i < 4; i++)
	{
		for (int j = 0; j < 4; j++)
		{
			printf("%lf\t", localToWorld.ptr()[j * 4 + i]);
		}
		cout << endl;
	}
	cout << endl;

	double x = 117;
	double y = 37;
	double z = 10.3;
	osgEarth::GeoPoint geoPoint(spatialReference, x, y, z);

	cout << "ECEF坐标（世界坐标）：";
	osg::Vec3d out_world;
	geoPoint.toWorld(out_world);
	cout << out_world.x() << '\t' << out_world.y() << '\t' << out_world.z() << endl;

	cout << "ENU坐标（局部坐标）：";
	osg::Vec3d localCoord = worldToLocal.preMult(out_world);
	cout << localCoord.x() << '\t' << localCoord.y() << '\t' << localCoord.z() << endl;
}

int main()
{
	//TestBLH2XYZ();

	cout << "使用Eigen进行转换实现：" << endl;
	TestXYZ2ENU();

	cout << "---------------------------------------" << endl;
	cout << "通过OsgEarth进行验证：" << endl;
	TestOE();
}